1. Field of the Invention
The present invention relates to an autonomous mobile robot, and more specifically, to an autonomous mobile robot which can autonomously move with legs connected under an upper body.
2. Description of the Related Art
An autonomous mobile robot includes an obstacle detector to detect an obstacle to avoid the obstacle or the like. For instance, an autonomous mobile device is disclosed in JP 2002-202815A, which includes, as obstacle detectors, a scanning sensor (such as a laser radar) for detecting position of an obstacle by scanning a horizontal plane in a front region and a non-scanning obstacle sensor (such as an ultrasonic sensor and an infrared sensor) for detecting an obstacle within a space other than where the scanning sensor can scan. The autonomous mobile device usually detects an obstacle in the front region with the scanning sensor (such as a laser radar) and operates the non-scanning obstacle sensor (such as an ultrasonic sensor and an infrared sensor) only when an obstacle is detected by the scanning sensor.
Accordingly, the autonomous mobile device can estimate the position of the obstacle with the both sensors so as to allow efficient detection and movement to avoid an obstacle.
By the way, the autonomous mobile device disclosed in JP 2002-202815A can detect an obstacle or the like in a front region with the scanning sensor and the non-scanning obstacle sensor, but cannot detect an obstacle in a rear region of the autonomous mobile device other than the front region of the autonomous mobile device.
Thus, for instance, the autonomous mobile device cannot detect an obstacle just behind the autonomous mobile device. Consequently, on moving backward, the autonomous mobile device cannot move properly in response to an obstacle in the rear region of the autonomous mobile device in spite of being able to move backward. Moreover, the autonomous mobile device cannot recognize an object (for instance, a man) approaching from the rear.